Outcomes of bee sting injury: comparison of hornet and paper wasp

Endothelial dysfunction of the cornea after exposure to sprayed venom from hornets

PURPOSE

Ocular injuries due to Hymenoptera venom are uncommon and most injuries occur on the ocular surface. We reported two rare cases of corneal endothelial damage caused by hornet venom that was sprayed, not injected, through stinging in the eye.

OBSERVATIONS

Case 1: A 57-year-old male patient was injured when a hornet sprayed venom into his left eye. He was referred to our hospital because the edoema and epithelial erosion of the cornea persisted. The patient presented with bullous keratopathy, asymmetrical iris atrophy, irreversible mydriasis, and glaucoma. His cataract progressed, and his best-corrected visual acuity was 0.03. Cataract surgery was performed after anti-inflammatory treatment with steroids, and Descemet-stripping automated endothelial keratoplasty was performed 6 months later. The patient recovered well postoperatively: his best-corrected visual acuity improved to 1.0 and he continued his glaucoma treatment. Case 2: A 75-year-old male patient had damage to his corneal epithelium, severe conjunctivitis, and conjunctival edoema when sprayed hornet venom entered his left eye. At initial presentation, the corneal endothelial cell density had decreased to 1042 cells/mm2. The conjunctival sac was washed, and steroid and topical antibacterial instillations were administered. His best-corrected visual acuity improved from 0.07 at the initial visit to 0.5. However, the corneal opacification and glaucoma persisted, and 3 months later the corneal endothelial cell density decreased to 846 cells/mm2.

CONCLUSIONS AND IMPORTANCE

Corneal injuries caused by sprayed hornet venom are rare; however, they can cause intense anterior chamber inflammation and severe, irreversible corneal endothelial damage. In such cases, prompt initial treatment, the administration of adequate anti-inflammatory medication, and careful evaluation of the corneal endothelium are required.

Development and internal validation of a Wasp Sting Severity Score to assess severity and indicate blood purification in persons with Asian wasp stings

Background

In recent years, the incidence of wasp sting has increased annually in China. Organ damage and high mortality due to mass wasp envenomation remain major challenges. Timely and appropriate medical intervention can improve survival. However, there are currently no normalized tools for early assessment of severity.

Methods

The clinical data of wasp sting patients hospitalized from 2011 to 2019 were used as a training set. Logistic regression was used to explore major risk factors for the development of a severe case of wasp sting (SC). The Wasp Sting Severity Score (WSS) was determined considering these risk factors to identify SCs and was tested in a validation dataset that was prospectively collected in 2020.

Results

The data of 1131 wasp sting patients from 2011 to 2019 were included in the training set. Logistic regression analysis showed that tea-colored urine, number of stings, and lactate dehydrogenase and total bilirubin levels were risk factors for developing an SC. The WSS was developed considering these four risk factors, and the total possible WSS was 20 points. The WSS was tested using the validation dataset, comprising the data of 153 patients, in 2020, and we found that a WSS ≥3 points was an important indication for blood purification, with a sensitivity of 71.9%, specificity of 92.6% and an area under the curve of 0.918 (95% confidence interval 0.873–0.962). Among patients with more than 30 stings, mortality in those who underwent plasma exchange (PE) within 24 h after admission was significantly lower than that in those who did not receive PE treatment (14.3% versus 46.9%, P = 0.003). However, continuous venovenous hemofiltration (CVVH) (P = 0.317) and hemoperfusion (HP) (P = 0.869) did not significantly reduce mortality.

Conclusions

Patients with WSS scores ≥3 should be considered for blood purification as early as possible in addition to routine treatment. In addition, PE is better than CVVH and HP at reducing mortality in patients suffering from severe wasp stings.

Ocular Injury Caused by the Sprayed Venom of the Asian Giant Hornet (Vespa mandarinia)

This report presents the details of a case of sight-threatening injury in the right eye of a 77-year-old man which was caused by the venom of the Asian giant hornet (Vespa mandarinia). The patient was not stung, rather the venom was sprayed into his eye. Although the injured eye was washed as a first aid treatment, persistent corneal defect, corneal endothelial decompensation, iris atrophy, pupil dilation, and mature cataract were observed and a hand movement visual acuity was recorded 8 weeks after the injury. Since a slight a-wave was detected in his electroretinogram (ERG) result after the corneal epithelial defect had healed, we performed cataract surgery and Descemet stripping automated endothelial keratoplasty (DSAEK). After the DSAEK, the cornea of the right eye became clearer; however, the visual acuity of his right eye did not improve. Fundus examination revealed branch retinal artery occlusion but no optic disc atrophy. ERG showed that the a-wave amplitude of the injured eye recorded after the surgery was almost half of that of the fellow eye. The iris atrophy and mature cataract show that the sprayed Vespa venom of the Asian giant hornet can permeate into the intraocular area even without stinging. Whether the venom directly affects retinal function is unclear, but the decreased a-wave of the injured eye shows that the venom caused damage of retinal function in some way. Irrigation of the anterior chamber as well as eye washing is needed as a first aid treatment in similar cases.

Diversity of compounds in Vespa spp. venom and the epidemiology of its sting: a global appraisal

Poisonous animals imply a risk to human life, because their venom is a complex mixture of low molecular weight components, peptides and proteins. Hornets use the venom for self-defence, to repel intruders and to capture prey, but they can cause poisoning and allergic reactions to people. In particular, they seem to be a health problem in the countries where they are native due to their sting, which in the most severe cases can lead to severe or fatal systemic anaphylaxis. But this situation is being an emerging problem for new countries and continents because hornet incursions are increasing in the global change scenario, such as in Europe and America. Furthermore, 55 detailed cases of hornet sting were found in 27 papers during the current review where 36.4% died due to, mainly, a multi-organ failure, where renal failure and liver dysfunction were the most common complications. Moreover, the great taxonomic, ecological diversity, geographical distribution and the wide spectrum of pathophysiological symptoms of hornets have been the focus of new research. Considering this, the present systematic review summarizes the current knowledge about the components of Vespa venom and the epidemiology of its sting to serve as reference for the new research focused on the development of techniques for diagnosis, new drugs and treatments of its sting.

Wasp sting of the cornea

Purpose

Many treatments, such as conservative management or penetrating keratoplasty, exist for corneal wasp sting. Here, we report a case of paper wasp sting of the cornea treated by anterior chamber wash immediately following admission, which soon resolved the inflammation.

Case

A healthy 9-year-old boy who had been stung by a paper wasp on his left eye 2 days prior to presentation at Dokkyo Medical University Saitama Medical Center was found to have corneal opacity accompanied by ciliary injection. The boy had difficulty opening his left eye due to pain. His left corneal endothelial cell density was 2,789 cells/mm², which was relatively lesser than that in the right eye. We diagnosed a paper wasp sting of the cornea based on both the patient’s clinical findings and sting history. The anterior chamber was promptly irrigated using a balanced salt solution; the inflammation resolved in a few hours, and the patient could open his left eye easily the following day. One day after the operation, the visual acuity improved to 1.2, and only slight corneal opacity remained at the original wasp sting site.

Conclusion

The positive outcome of the current case suggested that anterior chamber irrigation leads to rapid resolution of the inflammation.